Problem: $4pr + 9q - 6r - 2 = -9q + r + 4$ Solve for $p$.
Explanation: Combine constant terms on the right. $4pr + 9q - 6r - {2} = -9q + r + {4}$ $4pr + 9q - 6r = -9q + r + {6}$ Combine $r$ terms on the right. $4pr + 9q - {6r} = -9q + {r} + 6$ $4pr + 9q = -9q + {7r} + 6$ Combine $q$ terms on the right. $4pr + {9q} = -{9q} + 7r + 6$ $4pr = -{18q} + 7r + 6$ Isolate $p$ ${4}p{r} = -18q + 7r + 6$ $p = \dfrac{ -18q + 7r + 6 }{ {4r} }$